Lipids in Food

Question 1

Lipids make food more _______.

Answer 1

Palatable

Question 2

What is lipids importance in nutrition?

Answer 2

Provide lipid bilayers
Supplies 33-34% of calories
Provides essential fatty acids (omega 3 and 6)
Vitamin carrier (A, D, E)

Question 3

What is lipids importance in palatability?

Answer 3

Flavour
Texture
Influence of appetite

Question 4

What is lipids importance in processing?

Answer 4

Heat transfer = frying

Lubrication

Question 5

Are lipids soluble or insoluble in water?

Answer 5

Insoluble

Question 6

What are the three lipid classes in foods?

Answer 6

1. Simple (fatty acids, mono-, di-, triglycerides)
2. Compound (phosphoglycerides, glycolipids)
3. Derived (sterols)

Question 7

How are fatty acids connected to the glycerol backbone?

Answer 7

By ester bonds

Question 8

What fatty acids does a simple triglyceride have?

Answer 8

All the same

Question 9

What fatty acids does a mixed triglyceride have?

Answer 9

All different

Question 10

What are the four components of phosphoglycerides?

Answer 10

Choline
Phosphate
Glycerol
Fatty acids

Question 11

What is a fatty acid?

Answer 11

Chains of carbon and hydrogen atoms with a terminal carboxyl group

Question 12

What do the fatty acids in a lipid determine?

Answer 12

The properties of the lipid

Question 13

What is a saturated fatty acid?

Answer 13

Carbon and hydrogen chain with no double bond

Question 14

What is an unsaturated fatty acid?

Answer 14

Carbon and hydrogen chain with one or more double bond

Question 15

What are trivial names of fatty acids derived from?

Answer 15

The source

- Palmitic acid is derived from palm

Question 16

How are fatty acids named in the IUPAC system?

Answer 16

Derived from the number of carbons and whether the fatty acid is saturated or unsaturated

• Anoic = saturated
• Enoic = unsaturated
• 9-octadecenoic = 8 carbons with a double bond at the 9th carbon

Question 17

How are fatty acids named in the carboxyl reference system?

Answer 17

Indicates the number of carbons and the positioning of double bonds

• Carboxyl carbon = 1
• 18 : 2 Δ 9, 12 = 18 carbons, 2 double bonds at carbons and 12

Question 18

How are fatty acids named in the omega labelling system?

Answer 18

Indicates the number of carbons and positioning of double bonds

• Carbon furthest from carboxyl group = 1
• 18 : 3 (ω-3) = 18 carbons, 3 double bonds, the first double bond is at carbon 3

Question 19

What is a cis double bond?

Answer 19

Alkyl groups on the same side

Question 20

What is a trans double bond?

Answer 20

Alkyl groups on different sides = creates a kink in the chain